This is an active FM/AM/SW radio receiver antenna, can be used for FM radio receiver, AM radio receiver and SW (shortwave) radio receiver.
This circuit use active component JFET VHF Amplifier MPF102 to boost the radio signal. It use 9VDC supply to work.
On the shortwave band this active antenna is comparable to a 20 to 30 foot wire antenna. This circuit is designed to be used on receivers that use untuned wire antennas, such as inexpensive units and car radios.
L1 can be selected for the application. A 470uH coil works on lower frequencies ( AM ). For shortwave, try a 20uH coil. The unit can be powered by a 9 volt battery. If a power supply is used, bypass the power supply with a .04uF capacitor to prevent noise pickup. The antenna used on this circuit is a standard 18″ telescoping type. Output is taken from jack J1 and run to the input on the receiver.
Hi TNX FOR SHARING !!!
I want to use this circuit to improve the sensitivity of the radio I built out of an inductive tuner from a old T V.
It tunes from 50 MHZ to 220 MHZ so it covers channel 2 to 13 which includes the FM band that is between channel 6 & 7. The tuner input is 300 ohms so I’m wondering if I can use a ballet coil to match this amps output to the 300 ohm input of my radio. What is the impedance of the output of this amplifier. If there is something better that I can do I would appreciate any and all suggestions.
I also want to have a 0 center tuning meter. Does anyone have a circuit I can use for this? I have a nice Zero center analog meter movement. I would post pictures if I knew how
Pls, its very urgent cos I must complete my project before 12th of this month.I can’t get mpf102 in nigeria here,pls which transistor is d best substitute and what value of d inductor can i use for fm? Pls, help me…
I have built this before, but I am wondering how I can make it better for the long wave bands? Do I change the capacitors to higher value such as 1000 pF?